Underground storage tank metering system in a service station environment

ABSTRACT

A meter coupled in close proximity to an underground storage tank fuel pipe that delivers fuel from the underground storage tank to fuel dispensers in a service station environment. The meter measures the total amount of fuel drawn from the underground storage tank. The meter may be placed in a submersible turbine pump or in the main conduit that carries fuel to the fuel dispensers. The meter measurement is compared to the meter measurements in the individual fuel dispensers that receive the fuel drawn from the underground storage tank to determine if a discrepancy exists. A discrepancy may be indicative of meter tampering, meter calibration issues, and/or a leak in the fuel pipeline between the underground storage tank and the fuel dispensers. A leak detection test may be automatically performed if such discrepancy exists and/or an alarm condition generated and communicated.

FIELD OF THE INVENTION

[0001] The present invention relates to a meter coupled to anunderground storage tank that measures fuel delivered to fuel dispensersin a service station environment.

BACKGROUND OF THE INVENTION

[0002] In service station environments, fuel is stored underneath theservice station in underground storage tanks (USTs). The USTs typicallyhold thousands of gallons of fuel. In order to transfer fuel from theUSTs to fuel dispensers above the ground in the service stationforecourt so that the fuel can be dispensed to vehicles, a submersibleturbine pump (STP) is provided. The STP comprises a turbine and motorthat draws fuel from the UST. After the fuel leaves the STP, the fuel isdistributed via a main fuel piping conduit through the service station.Individual fuel dispensers draw fuel from the main fuel piping conduitvia a branch conduit that is fluidly coupled to the main fuel pipingconduit. The fuel is then delivered into the fuel dispenser, metered anddispensed to a vehicle through a hose and nozzle combination.

[0003] Each of the individual fuel dispensers contains meters thatmeasure the amount of fuel dispensed to a vehicle. Since this fueloriginates from USTs, the amount of fuel dispensed out of the USTs isthe combination of all of the metered fuel dispensed out of theindividual fuel dispensers. The fuel dispenser meter data iscommunicated to a single site controller (SC) at the service station.The SC uses the individual fuel dispenser meter data to track theinventory levels of the USTs and to generate reports on this inventory.The SC may also provide fuel dispenser meter data information to a tankmonitor (TM) system as is described in U.S. Pat. Nos. 5,665,895;5,544,518; and 4,977,528, all of which are incorporated by reference intheir entirety. The TM uses the fuel dispenser meter data as a referencepoint to calibrate the tank-strapping curve for the UST. Atank-strapping curve is a curve that correlates a liquid level in theUST to a volume level.

[0004] There are several factors that could cause the fuel dispensermeter data to not be an accurate account of the amount of fuel drawn outof the USTs and delivered to the fuel dispensers. First, a person couldhave tampered with the fuel dispenser meter and/or electronics such thatthe amount of fuel dispensed to a vehicle is different than measured bythe fuel dispenser meter. In a typical fraud scenario, the fueldispenser meter is tampered to measure more fuel than is actuallydispensed so that customers get charged for more fuel than is dispensed.Second, the fuel dispenser meter may not be properly calibrated. Thiswill cause the fuel dispenser meter to not accurately reflect the amountof fuel dispensed. Third, there may be a leak present in the fuel pipingbetween the UST and the fuel dispenser meters, which will cause theamount of fuel drawn out of the UST to be less that the amount of fuelmeasured and delivered by the fuel dispenser.

[0005] If any of the aforementioned events occur, the fuel dispensermeter data that is collected by the SC will not be accurate as well. Ifthe TM uses the fuel dispenser meter data from the SC for calibration ofthe tank-strapping curve, the tank strapping curve will be inaccurate aswell. Further, this condition could go unnoticed for long periods oftime.

[0006] Therefore, there exists a need to be able to confirm absolutelythe amount of fuel drawn out of the USTs so that this amount can becompared to the fuel dispenser meter measurements to ensure that fraud,calibration, and/or leak issues are not present in the service stationenvironment. Further, it may be important to base the tank-strappingcurve calibration on another baseline of the amount of fuel drawn out ofthe UST rather than using the measurements of the individual fueldispenser meters.

SUMMARY OF THE INVENTION

[0007] The present invention relates to placement of a meter in the fuelpiping that carries fuel drawn out of an underground storage tank (UST)to fuel dispensers in a service station environment. The meter measuresall of the fuel that is drawn out of the UST before the fuel isdelivered via the main and branch conduits to the individual fueldispensers.

[0008] The meter may be placed inline to the fuel piping that deliversthe fuel from the UST to the fuel dispensers, including in thesubmersible turbine pump (STP) and any other location in the mainconduit. The meter may be a positive displacement or inferential meter.A turbine meter is used in one embodiment since turbine meters are knownto require minimal or no recalibration after the meter is installed andoperational.

[0009] A controller compares the amount of fuel drawn from the UST anddelivered to the individual fuel dispensers with the fuel measured bythe individual fuel dispenser meters in order to determine if there is adiscrepancy. If not, the process continues in a looping fashion. Ifthere is a discrepancy, this is indicative of either fraud, a leak, or ameter(s) becoming uncalibrated. The controller may generate an alarm inresponse to detection of such discrepancy, and initiate a leak detectiontest to determine if there is a leak in the underground fuel piping.

[0010] Those skilled in the art will appreciate the scope of the presentinvention and realize additional aspects thereof after reading thefollowing detailed description of the preferred embodiments inassociation with the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawing figures incorporated in and forming apart of this specification illustrate several aspects of the invention,and together with the description serve to explain the principles of theinvention.

[0012]FIG. 1 illustrates communication connections in an exemplaryfueling environment;

[0013]FIG. 2 illustrates fluid connections in an exemplary fuelingenvironment;

[0014]FIG. 3A illustrates a meter coupled inline to fuel piping thatcarries fuel drawn from an underground storage tank (UST) to fueldispensers;

[0015]FIG. 3B illustrates an alternative configuration to FIG. 3Awherein the meter is coupled in the submersible turbine pump (STP)housing;

[0016]FIG. 3C illustrates an alternative configuration to FIG. 3Ahousing; and

[0017]FIG. 4 illustrates a flowchart diagram of using the metered amountof fuel from the UST to perform diagnostic operation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The embodiments set forth below represent the necessaryinformation to enable those skilled in the art to practice the inventionand illustrate the best mode of practicing the invention. Upon readingthe following description in light of the accompanying drawing figures,those skilled in the art will understand the concepts of the inventionand will recognize applications of these concepts not particularlyaddressed herein. It should be understood that these concepts andapplications fall within the scope of the disclosure and theaccompanying claims.

[0019] Fueling environments come in many different designs. Beforedescribing the particular aspects of the present invention (which beginsat the description of FIG. 3), a brief description of a fuelingenvironment follows. A conventional, exemplary fueling environment 10 isillustrated in FIGS. 1 and 2. Such a fueling environment 10 may comprisea central building 12, a car wash 14, and a plurality of fueling islands16.

[0020] The central building 12 need not be centrally located within thefueling environment 10, but rather is the focus of the fuelingenvironment 10, and may house a convenience store 18 and/or a quickserve restaurant 20 therein. The convenience store 18 and/or quickserver restaurant 20 may also be present at a truck stop facility ratherthan a primary non-truck vehicle filling station. Both the conveniencestore 18 and the quick serve restaurant 20 may include a point of sale22, 24, respectively. The central building 12 may further house a sitecontroller (SC) 26, which in an exemplary embodiment may be the G-SITE®sold by Gilbarco Inc. of Greensboro, N.C. The SC 26 may control theauthorization of fueling transactions and other conventional activitiesas is well understood. The SC 26 may be incorporated into a point ofsale, such as point of sale 22, if needed or desired. Further, the SC 26may have an off-site communication link 28 allowing communication with aremote location for credit/debit card authorization, content provision,reporting purposes, or the like, as needed or desired. The off-sitecommunication link 28 may be routed through the Public SwitchedTelephone Network (PSTN), the Internet, both, or the like, as needed ordesired.

[0021] The car wash 14 may have a point of sale 30 associated therewiththat communicates with the SC 26 for inventory and/or sales purposes.The car wash 14 alternatively may be a stand alone unit. Note that thecar wash 14, the convenience store 18, and the quick serve restaurant 20are all optional and need not be present in a given fueling environment10.

[0022] The fueling islands 16 may have one or more fuel dispensers 32positioned thereon. The fuel dispensers 32 may be, for example, theECLIPSE® or ENCORE® sold by Gilbarco Inc. of Greensboro, N.C. The fueldispensers 32 are in electronic communication with the SC 26 through aLAN or the like.

[0023] The fueling environment 10 also has one or more undergroundstorage tanks (USTs) 34 adapted to hold fuel therein. As such, the UST34 may be a double-walled tank. Further, each UST 34 may be associatedwith a tank monitor (TM) 36, or one TM 36 may handle all the USTs 34.The TMs 36 typically have fluid level sensors and other data gatheringdevices positioned in the USTs 34 which are communicatively coupled tothe TM 36. In some implementations, the TM 36 may be positioned in thecentral building 12; however, because the TMs 36 monitor fluid levelswithin the USTs 34, the TMs 36 are shown schematically positioned nextto the USTs 34. The TMs 36 may communicate with the fuel dispensers 32(either through the SC 26 or directly, as needed or desired) todetermine amounts of fuel dispensed and compare fuel dispensed tocurrent levels of fuel within the USTs 34 as reported by the sensors todetermine if the USTs 34 are leaking.

[0024] The TM 36 may communicate with the SC 26 and further may have anoff-site communication link 38 for leak detection reporting, inventoryreporting, or the like. Much like the off-site communication link 28,the off-site communication link 38 may be through the PSTN, theInternet, both, or the like. If the off-site communication link 28 ispresent, the off-site communication link 38 need not be present and viceversa, although both links may be present if needed or desired. Further,the off-site communication links 28, 38 may be incorporated into onesingle link. Further, the off-site communication link 28 may beassociated with a back-office system (BOS) (not shown) rather than a SC26 since a SC 26 may be linked to a BOS. As used herein, the TM 36 andthe SC 26 are site communicators to the extent that they allow off-sitecommunication and report site data to a remote location.

[0025] For further information on how elements of a fueling environment10 may interact, reference is made to U.S. Pat. No. 5,956,259, which ishereby incorporated by reference in its entirety. Information about fueldispensers may be found in commonly owned U.S. Pat. Nos. 5,734,851 and6,052,629, which are hereby incorporated by reference in their entirety.Information about car washes may be found in commonly owned U.S. patentapplication Ser. No. 60/380,111, filed 06 May 2002, entitled “Improvedservice station car wash,” which is hereby incorporated by reference inits entirety. An exemplary TM 36 is the TLS-350R manufactured and soldby Veeder-Root. For more information about TMs and their operation,reference is made to U.S. Pat. Nos. 5,423,457; 5,400,253; 5,319,545; and4,977,528, which are hereby incorporated by reference in theirentireties.

[0026] In addition to the various conventional communication linksbetween the elements of the fueling environment 10, there areconventional fluid connections to distribute fuel about the fuelingenvironment 10 as illustrated in FIG. 2. USTs 34 may each be associatedwith a vent 40 that allows over-pressurized tanks to relieve pressurethereby. A pressure valve (not shown) is placed on the outlet side ofeach vent 40 to open to atmosphere when the pressure in the UST 34reaches a predetermined threshold. Additionally, under-pressurized tanksmay draw air in through the vents 40. In an exemplary embodiment, twoUSTs 34 exist—one a low octane tank (87) and one a high-octane tank(93). Blending may be performed within the fuel dispensers 32, as iswell understood, to achieve an intermediate grade or grades of fuel.Alternatively, additional USTs 34 may be provided for diesel and/or anintermediate grade of fuel (not shown). The vents 40 may be coupled to apost-processing system that is designed to filter hydrocarbons out of avapor/air mixture in the UST 34 that is released through the vents 40when a pressure valve (not shown) in the vents 40 opens after athreshold pressure is reached in the UST 34, like that described in U.S.Pat. Nos. 5,464,466; 5,571,310; 5,626,649; 5,755,854; 5,843,212;5,985,002; and 6,293,996, all of which are incorporated herein byreference in their entireties.

[0027] Pipes 42 connect the USTs 34 to the fuel dispensers 32. The pipes42 may be arranged in a main conduit 44 (also called a main fuel piping)and branch conduit 46 configuration, where the main conduit 44 carriesthe fuel from the USTs 34 to the branch conduits 46, and the branchconduits 46 connect to the fuel dispensers 32. Typically, the pipes 42are double-walled pipes comprising an inner conduit and an outerconduit. Fuel flows in the inner conduit to the fuel dispensers 32, andthe outer conduit insulates the environment from leaks in the innerconduit. For a better explanation of such pipes and concerns about howthey are connected, reference is made to Chapter B13 of PIPING HANDBOOK,7^(th) edition, copyright 2000, published by McGraw-Hill, which ishereby incorporated by reference.

[0028] In a typical service station installation, leak detection may beperformed by a variety of techniques, including probes and leakdetection cables. More information about such devices can be found inthe previously incorporated PIPING HANDBOOK. Conventional installationscapture the leaked fuel in low point sumps, sumps in the fuel dispensers32, or the like, where the fuel mixes with contaminants such as dirt,water, and the like, thereby ruining the fuel for future use withoutprocessing.

[0029] While not shown, vapor recovery systems may also be integratedinto the fueling environment 10, with vapor recovered from fuelingoperations being returned to the USTs 34 via separate vapor recoverylines (not shown). For more information on vapor recovery systems, theinterested reader is directed to U.S. Pat. Nos. 5,040,577; 6,170,539;and Re. 35,238; and U.S. patent application Ser. No. 09/783,178 filed 14Feb. 2001, all of which are hereby incorporated herein by reference intheir entireties.

[0030] Now turning to the present invention, as illustrated in FIGS.3A-3C, a submersible turbine pump (STP) 48 is shown that is fluidlycoupled to the UST 34. The STP 48 is contained inside a sump 50. Thesump 50 captures any fuel leaks that occur in the STP 48. The sump 50may contain a sump sensor 64 that detects any fuel 51 that leaks fromthe STP 48. If the main conduit 44 is single-walled piping, activetesting must take place to detect leaks including detection of leaks inthe sump 50 using the sump sensor 64 and fuel dispenser sumps (notshown). The sump sensor 64 may be any type of leak detection sensor.

[0031] The STP 48 comprises a STP housing 52 for control electronics(not shown). The STP 48 is fluidly coupled to the fuel 51 in the UST 34via a fuel piping (not shown) contained inside a riser pipe 54 and boom56. The boom 56 is connected to a turbine housing 58 that contains aturbine (not shown). The STP 48 is typically mounted to the UST 34 usinga mounting plate 62. The control electronics causes the turbine torotate and pressurize the inside of the turbine housing 58 and the boom56 thereby drawing fuel 51 from the UST 34 through a turbine housinginlet 60. The fuel 51 travels upward through the fuel piping extendingfrom the turbine housing 58 through the boom 56 and riser pipe 54 to theSTP housing 52. The main conduit 44 is coupled to the STP housing 52 tocarry fuel 51 drawn from the UST 34 to the branch conduits 46.

[0032] For a more complete explanation of the STP 48 and supportingcomponents, reference is made to U.S. Pat. No. 6,223,765 assigned toMarley Pump Company, which is incorporated herein by reference in itsentirety, and the product exemplifying the teachings of the patentexplained in Quantum Submersible Pump Manual: Installation andOperation, also produced by the Marley Pump Company, also incorporatedby reference in its entirety.

[0033] In FIG. 3A, a first embodiment of the invention is disclosed. Ameter 70 is placed inline to the main conduit 44 to measure the totalamount of fuel 51 drawn out of the UST 34. In this manner, the totalamount of fuel 51 drawn out of the UST 34, via the STP 48 describedabove, is measured in the branch conduit 46 at one location rather thandownstream after the main conduit 44 has split into branch conduits 46.Since USTs 34 only store one grade or octane of fuel, the systemillustrated in FIG. 3A is for measuring the total amount of fuel 51drawn out of a given UST 34. If multiple grades of fuel 51 are stored inmultiple USTs 34, multiple systems like that described in FIG. 3A may beused. A leak detection sensor 68 may also be placed in the inner annularspace of the main conduit 44 to detect leaks, as is well known.

[0034] The meter 70 may any type of meter, including but not limited topositive displacement or inferential meter. Since the meter 70 is in alocation not necessarily easily accessible by service personnel, it maybe advantageous to use a meter 70 that requires minimal or nocalibration. One such meter is known as a turbine flow meter, as isdescribed in U.S. Pat. No. 5,689,071, entitled “Wide range, highaccuracy flow meter,” incorporated herein by reference in its entirety.The turbine flow meter is an inferential meter and its advantages aredescribed in the '071 Patent as well as co-pending U.S. patentapplication Ser. No. 10/227,746, filed on Aug. 26, 2002 entitled“Multi-metal turbine sensing for increased sensitivity and reducedcost,” incorporated herein by reference in its entirety.

[0035] The main conduit 44 may be single walled piping or double-walledpiping like that described in co-pending U.S. patent application Ser.No. 10/173,990, filed on Jun. 18, 2002 entitled “Service station leakdetection and recovery system,” incorporated herein by reference in itsentirety.

[0036] If the main conduit 44 is double-walled piping, the meter 70 isconfigured to maintain the separation of the inner annular space and theouter annular space of the double-walled piping such that the secondarycontainment provided by the outer annular space of the double walledpiping is maintained throughout the meter 70 and on the outlet side ofthe meter 70. The meter 70 may provide a path for the outer annularspace of the double walled piping to divert around the meter 70, or themeter 70 may be configured to accept a double-walled piping as an inputand output and maintain the integrity of the outer annular space.

[0037] Before the present invention, no meter 70 was used to measure thetotal amount of fuel 51 drawn out of the UST 34. Measurements fromindividual meters in fuel dispensers 32 were totaled up to derive thetotal amount of fuel 51 drawn from a UST 34. The individual fueldispenser 32 meters only receive the fuel 51 drawn from the UST 34 afterthe fuel 51 travels from the STP 48 through a main conduit 44 and intobranch conduits 46 coupled to the individual fuel dispenser 32 meters.There could be any number of reasons that the individual fuel dispenser32 meters will not accurately measure the amount of fuel 51 drawn from aUST 34. First, a person could have tampered with the fuel dispenser 32meter and/or electronics such that the amount of fuel 51 dispensed to avehicle is different than measured by the fuel dispenser 32 meter. In atypical fraud scenario, the fuel dispenser 32 meter is tampered tomeasure more fuel than is actually dispensed so that customers getcharged for more fuel than is dispensed. Second, the fuel dispenser 32meter may not be properly calibrated. This will cause the fuel dispenser32 meter to not accurately reflect the amount of fuel 51 dispensed.Third, there may be a leak present in the main conduit 44 or branchconduits 46 between the UST 34 and the fuel dispenser 32 meters, whichwill cause the amount of fuel 51 drawn out of the UST 34 to be less thatthe amount of fuel 51 measured and delivered by the fuel dispensers 32.

[0038] If any of the aforementioned events occur, the fuel dispenser 32meter data that is collected by the SC 26 will not be accurate as well.If the TM 36 uses the fuel dispenser 32 meter data from the SC 26 forcalibration of the tank-strapping curve, as is described for example inU.S. Pat. Nos. 4,977,528; 5,544,518; 5,665,895, all of which areincorporated herein by reference in their entireties, the tank-strappingcurve will be inaccurate as well. More information on the operationalaspects of the present invention is provided below in FIGS. 4-6; butfirst, alternative meter 70 placement configurations are described belowfor FIGS. 3B and 3C.

[0039]FIG. 3B illustrates an alternative placement of the meter 70. InFIG. 3B, the meter 70 is placed in the STP 48 and specifically in theSTP housing 52. In this embodiment, the meter 70 is placed in the STP 48which is inside the sump 50 so that any leaked fuel around the meter 70is captured in the sump 50. In this manner, it is not necessary for themeter 70 to accept the outer annular space of the main conduit 44 or toprovide a bypass of the outer annular space of the main conduit 44around the meter 70, if the main conduit 44 is double-walled piping.

[0040]FIG. 3C illustrates another alternative placement of the meter 70,wherein the meter 70 is placed in the turbine housing 58. All of theprevious discussion regarding the meter 70 that is discussed in FIG. 3Aand 3B is also applicable here and is therefore not repeated.

[0041] In summary, the meter 70 may be placed in any location in the STP48, including the turbine housing 58, the boom 56, the riser pipe 54,the STP housing 48, and the main conduit 44, such that the meter 70receives all fuel 51 drawn from the UST 34 at a single location in orderto measure the total amount of fuel 51 drawn from the UST 34 to be laterdelivered to the fuel dispensers 32.

[0042] In each of the aforementioned embodiments of the meter 70placement illustrated in FIGS. 3A-3C, the meter 70 generates a datasignal 72 that is indicative of the total amount of fuel 51 passingthrough the meter 70. The data signal 72 is a signal that represents thetotal amount of fuel 51 drawn from the UST 34. The signal 72 may be adirect representation of the total amount of fuel 51 or may be a signal72 that is used to derive the total amount of fuel 51. This data signal72 may be generated using a pulser as is described in U.S. Pat. No.6,109,477, entitled “Signature pulse generator and method of detectingtampering with a fueling operation.” This data signal 72 is electricallycoupled to either the SC 26, the TM 36, or other controller to calculatethe total amount of fuel 51 drawn from the UST 34. The SC 26, TM 36 orother controller also collects data from the individual fuel dispenser32 meters as well. In this application when the term “controller” isused, the controller may be the SC 26, the TM 36 or any other type ofcontroller that is capable of receiving the data signal 72 andcalculating the total amount of fuel 51 drawn from the UST 34. It iswith this information that the operational aspects of the presentinvention are described.

[0043]FIG. 4 illustrates the operational aspect of the present inventionwherein the total amount of fuel 51 measured by the meter 70 is comparedto the individual fuel measurements from the fuel dispenser 32 meters todetermine if there is a discrepancy. A discrepancy is an indication ofthree possible events. First, a leak could exist between the meter 70and the individual fuel dispenser 32 meters such that all of the fuel 51measured by the meter 70 never reaches one or more of the individualfuel dispenser 32 meters for measurement. A leak could exist in the mainconduit 44 or a branch conduit 46. Second, a fraudulent or tamperingactivity could have occurred at one or more of the individual fueldispenser 32 meters such that the meter data communicated to thecontroller 26, 36 is not accurate. Tampering in this manner usuallyinvolves causing one or more individual fuel dispenser 32 meters toregister an amount of fuel 51 greater than the actual amount of fuel 51passing through the fuel dispenser 32 meter so that the customer ischarged as if more fuel 51 was dispensed into his or her vehicle thanwas actually dispensed. Third, one or more of the individual fueldispenser 32 meters may not be properly calibrated or may be out ofcalibration such that the amount of fuel 51 measured by the individualfuel dispenser 32 meters is not accurate.

[0044] The processing carried out by the process illustrated in FIG. 4may be performed in the SC 26, the TM 36, other controller, or through acombination of these various control elements (hereineafter referred toas “controller”).

[0045] In FIG. 4, a process is illustrated where the controller 26, 36determines if there is a discrepancy between the amount of fuel 51measured from the meter 70 and the amount of fuel 51 measured by theindividual fuel dispensers 32. The process starts (block 100), and theamount of fuel measured by the meter 70 drawn from the UST 34 for aparticular grade of fuel 51 is determined using the data signal 72(block 102). Next, this amount of fuel from the meter 70 is compared tothe individual fuel dispenser 32 meter data received through the branchconduits 46 (block 104). If there is a discrepancy such that the amountof fuel 51 measured by the meter 70 from the UST 34 is greater than orless than the amount of fuel measured by the individual fuel dispenser32 meters by a threshold value (decision 106), an alarm conditionexists.

[0046] If the UST 34 for a particular grade of fuel 51 that is meteredby meter 70 contains a post-processor system for filtering the vapor/airmixture that is released through the vent 40 due to overpressureconditions in the UST 34, an optional feature would be for thecontroller 26, 36 to take any hydrocarbons released through the vent 40into consideration as calculating the amount of fuel in the in block102.

[0047] If no alarm condition exists (decision 106), the processcontinues in a looping fashion to check for a discrepancy between theamount of fuel 51 drawn from the UST 34, as measured by the meter 70(block 102), compared with the amount of fuel 51 measured by theindividual fuel dispensers 32 (block 104).

[0048] If an alarm condition exists, a general alarm is indicated suchthat it is known that there is either a leak in the main conduit 44 orbranch conduits between the meter 70 and the fuel dispenser 32 meter, orthe fuel dispenser 32 meter is miscalibrated or has been fraudulentlytampered with (block 108). The alarm condition may be communicated to auser, to the SC 26 and/or the TM 36. An alarm may comprise a visualand/or audio signal to an operator of the service station or to a remotelocation via the off-site communication link 28 or off-sitecommunication link 38, or both. The alarm condition may trigger certainpredefined steps of investigation including but not limited to a sitesurvey, shutting down the STP 48 associated with the meter 70, andperforming a line leak detection test. The alarm condition may also bestored in memory (not shown) associated with the controller 26, 36 in alog file and/or in a log file in memory associate with the remotelocation. Further, the remote location can send such alarm condition toanother location, including but not limited to headquarter sites,regulatory authorities, such as Weights & Measures, etc.

[0049] In addition, the TM 36 may be configured so that a line leakdetection test is automatically triggered once an alarm condition isgenerated (block 108). This is because at this point, it is not knownwhether the discrepancy between the fuel 51 measured by the meter 70from the UST 34 is different from that of the individual fuel dispenser32 meters because of a leak, fraud, or calibration issues. Given thefact that early leak detection is important in a service stationenvironment, it may be desirable for the system to automatically triggera leak detection test. This leak detection test may be any type of leakdetection test including but not limited to those described in U.S. Pat.Nos. 4,876,530 and 5,317,899, all of which are incorporated herein byreference in their entireties

[0050] If a leak detection test setting is indicated (decision 110), thecontroller 26, 36 will initiate a leak detection test (block 112). If aleak is detected (decision 114), any number of actions can be taken thatare normally taken, including but not limited to shutting down the STP48 associated with the UST 34 containing a particular grade of fuel(block 116), or generating an alarm. Thereafter, the process ends (block118) with respect to the particular UST 34 until the service actiontakes place. If a leak is not detected (decision 114), the controller26, 36 indicates an alarm that is indicative of either fraud ormiscalibration and not a leak since the line leak detection testresulted in no leak detected in decision 114. The process repeats itself(block 102) since the alarm condition was not generated as a result of aleak, and fuel 51 can still be dispensed from the UST 34 in anenvironmentally safe manner even though such alarm condition exists. Inan alternative embodiment, the STP 48 for the particular fuel dispenser32 where a discrepancy is found may be shut down, regardless of whetherthe alarm condition is indicative of a leak or not.

[0051] If the controller 26, 36 has the ability to receive fueldispenser 32 meter data from each fuel dispenser 32 meter on ameter-by-meter basis, the controller 26, 36 can perform the comparisonin block 104 for a particular fuel dispenser 32 meter on an individualmeter basis rather than collectively. Even if the controller 26, 36 doesnot have the ability to receive fuel dispenser 32 meter data from eachfuel dispenser 32 meter on a meter-by-meter basis, it may neverthelessstill be possible for the controller 26, 36 to deduce when a specificfuel dispenser 32 meter measures fuel in discrepancy with meter 70.

[0052] Those skilled in the art will recognize improvements andmodifications to the preferred embodiments of the present invention. Allsuch improvements and modifications are considered within the scope ofthe concepts disclosed herein and the claims that follow.

What is claimed is:
 1. An apparatus for metering fuel drawn out of anunderground storage tank and delivered to a fuel dispenser in a servicestation environment, comprising: a submersible turbine pump fluidlycoupled to fuel in the underground storage tank wherein said submersibleturbine pump draws the fuel out of the underground storage tank; a mainfuel piping coupled to said submersible turbine pump to carry the fueldrawn by said submersible turbine pump to the fuel dispenser; and ameter coupled inline to said main fuel piping that measures the amountof fuel drawn by said submersible turbine pump from the undergroundstorage tank and delivered to the fuel dispenser.
 2. The apparatus ofclaim 1, wherein said meter is a turbine meter.
 3. A system fordetecting a discrepancy between the amount of fuel drawn from anunderground storage tank to a plurality of fuel dispensers and theamount of fuel measured by the plurality of fuel dispensers, comprising:a controller; a submersible turbine pump fluidly coupled to fuel in theunderground storage tank wherein said submersible turbine pump draws thefuel out of the underground storage tank; a main fuel piping coupled tosaid submersible turbine pump to carry the fuel drawn by saidsubmersible turbine pump to the fuel dispenser; a meter coupled inlineto said main fuel piping that measures the amount of fuel drawn by saidsubmersible turbine pump from the underground storage tank and deliveredto the fuel dispenser, wherein said meter electronically communicatesthe amount of fuel drawn by said submersible turbine pump to saidcontroller; and a plurality of fuel dispensers that each receives thefuel from a branch fuel piping coupled to said main fuel piping, whereineach of said plurality of fuel dispensers contains a fuel dispensermeter to measure the amount of the fuel received from said branch fuelpiping and wherein said fuel dispenser meter electronically communicatesthe amount of fuel received from said branch conduit to said controller.4. The system of claim 3, wherein said meter is a turbine meter.
 5. Thesystem of claim 3, wherein said controller is included in a devicecomprised from the group consisting of a site controller and a tankmonitor.
 6. The system of claim 3, wherein said controller is adapted tocompare said amount of fuel received from said branch conduits and saidamount of fuel drawn by said submersible turbine pump and to determineany discrepancy between the amount of fuel received from said branchconduits and the amount of fuel drawn by said submersible turbine pump.7. The system of claim 6, wherein said controller generates an alarm ifsaid amount of fuel received from said branch conduits is different thansaid amount of fuel drawn by said submersible turbine pump.
 8. Thesystem of claim 7, wherein said alarm is comprised from the groupconsisting of a fraud alarm, a leak alarm, and a calibration alarm. 9.The system of claim 6, wherein said controller initiates a leakdetection test if said amount of fuel received from said branch conduitsis different than said amount of fuel drawn by said submersible turbinepump.
 10. The system of claim 9, wherein said leak detection test iscomprised from the group consisting of a leak detection test for saidmain fuel piping and a leak detection test for said branch fuel piping.11. The system of claim 9, wherein said leak detection test is comprisedfrom the group consisting of a gross leak detection test, a precisionleak detection test at 0.2 gallons per hour, and a precision leakdetection test at 0.1 gallons per hour.
 12. The system of claim 6,wherein said controller communicates any said discrepancy to a remotelocation.
 13. The system of claim 3, wherein said controller generatesan alarm when the amount of fuel drawn by said submersible turbine pumpexceeds a threshold level.
 14. The system of claim 13, wherein saidalarm is communicated to a remote location.
 15. The system of claim 3,wherein said controller determines which of said fuel dispenser metersin said plurality of fuel dispenser meters is in discrepancy with saidmeter.
 16. A method of installing a meter to measure the amount of fueldrawn from an underground storage tank and delivered to a fuel dispenserin a service station environment, comprising the steps of: fluidlycoupling a submersible turbine pump to fuel in the underground storagetank; coupling a main fuel piping to said submersible turbine pumpwherein said submersible turbine pump draws fuel from the undergroundstorage tank and delivers the fuel to said main fuel piping; and placinga meter inline to said main fuel piping that measures the amount of fueldrawn by said submersible turbine pump from the underground storagetank.
 17. An apparatus for metering fuel drawn out of an undergroundstorage tank and delivered to a fuel dispenser in a service stationenvironment, comprising: a submersible turbine pump fluidly coupled tofuel in the underground storage tank wherein said submersible turbinepump draws the fuel out of the underground storage tank; a main fuelpiping coupled to said submersible turbine pump to carry the fuel drawnby said submersible turbine pump to the fuel dispenser; and a meterplaced in said submersible turbine pump that measures the amount of fueldrawn by said submersible turbine pump from the underground storage tankand delivered to the fuel dispenser.
 18. The apparatus of claim 17,wherein said meter is a turbine meter.
 19. A system for detecting adiscrepancy between the amount of fuel drawn from an underground storagetank to a plurality of fuel dispensers and the amount of fuel measuredby the plurality of fuel dispensers, comprising: a controller; asubmersible turbine pump fluidly coupled to fuel in the undergroundstorage tank wherein said submersible turbine pump draws the fuel out ofthe underground storage tank; a main fuel piping coupled to saidsubmersible turbine pump to carry the fuel drawn by said submersibleturbine pump to the fuel dispenser; a meter placed in said submersibleturbine pump that measures the amount of fuel drawn by said submersibleturbine pump from the underground storage tank and delivered to the fueldispenser; and a plurality of fuel dispensers that each receives thefuel from a branch fuel piping coupled to said main fuel piping, whereineach of said plurality of fuel dispensers contains a fuel dispensermeter to measure the amount of the fuel received from said branch fuelpiping and wherein said fuel dispenser meter electronically communicatesthe amount of fuel received from said branch fuel piping to saidcontroller.
 20. The system of claim 19, wherein said meter is a turbinemeter.
 21. The system of claim 19, wherein said meter is placed in aturbine housing of said submersible turbine pump.
 22. The system ofclaim 19, wherein said meter is placed in a boom of said submersibleturbine pump.
 23. The system of claim 19, wherein said meter is placedin a riser pipe of said submersible turbine pump.
 24. The system ofclaim 19, wherein said meter is placed in a submersible turbine pumphousing of said submersible turbine pump.
 25. The system of claim 19,wherein said controller is included in a device comprised from the groupconsisting of a site controller and a tank monitor.
 26. The system ofclaim 19, wherein said controller is adapted to compare said amount offuel received from said branch conduits and said amount of fuel drawn bysaid submersible turbine pump and to determine any discrepancy betweensaid amount of fuel received from said branch conduits and said amountof fuel drawn by said submersible turbine pump.
 27. The system of claim26, wherein said controller generates an alarm if said amount of fuelreceived from said branch conduits is different than said amount of fueldrawn by said submersible turbine pump.
 28. The system of claim 27,wherein said alarm is comprised from the group consisting of a fraudalarm, a leak alarm, and a calibration alarm.
 29. The system of claim26, wherein said controller initiates a leak detection test if saidamount of fuel received from said branch conduits is different than saidamount of fuel drawn by said submersible turbine pump.
 30. The system ofclaim 29, wherein said leak detection test is comprised from the groupconsisting of a leak detection test for said main fuel piping and a leakdetection test for said branch fuel piping.
 31. The system of claim 29,wherein said leak detection test is comprised from the group consistingof a gross leak detection test, a precision leak detection test at 0.2gallons per hour, and a precision leak detection test at 0.1 gallons perhour.
 32. The system of claim 26, wherein said controller communicatesany said discrepancy to a remote location.
 33. A method of installing ameter to measure the amount of fuel drawn by a submersible turbine pumpfrom an underground storage tank and delivered to a fuel dispenser in aservice station environment, comprising the steps of: fluidly coupling asubmersible turbine pump to fuel in the underground storage tank;coupling a main fuel piping to said submersible turbine pump whereinsaid submersible turbine pump draws fuel from the underground storagetank and delivers the fuel to said main fuel piping; and placing a meterin said submersible turbine pump that measures the amount of fuel drawnby said submersible turbine pump from the underground storage tank. 34.A method of measuring the amount of fuel drawn from an undergroundstorage tank that is delivered to a plurality of fuel dispensers in aservice station environment, comprising the steps of: drawing an amountof fuel from the underground storage tank; and measuring the amount offuel drawn from the underground storage tank before the fuel isdelivered to the plurality of fuel dispensers.
 35. The method of claim34, further comprising the step of communicating said amount of fueldrawn from the underground storage tank to a controller.
 36. The methodof claim 34, further comprising the step of comparing the amount of fuelreceived by the plurality of fuel dispensers and the amount of fueldrawn from the underground storage tank and determining any discrepancybetween the amount of fuel received from the plurality of fueldispensers and the amount of fuel drawn from the underground storagetank.
 37. The method of claim 36, further comprising the step ofgenerating an alarm if said amount of fuel received from said branchconduits is different than said amount of fuel drawn from theunderground storage tank.
 38. The method of claim 36, further comprisingthe step of initiating a leak detection test if said amount of fuelreceived from said branch conduits is different than said amount of fueldrawn from the underground storage tank.
 39. The method of claim 36,further comprising the step of communicating any said discrepancy to aremote location.
 40. The method of claim 36, further comprising thestopping the draw of fuel from the underground storage tank if saidamount of fuel received from said branch conduits is different than saidamount of fuel drawn from the underground storage tank.
 41. The methodof claim 38, further comprising the stopping the draw of fuel from theunderground storage tank if said leak detection test fails.